1. Field of the Invention
The present invention relates to an axial piston pump or motor in which pistons are respectively supported in a plurality of cylinder bores formed in a cylinder in a manner so as to surround the axis thereof, where the pistons are reciprocatingly moved in the direction of the axis by a swashplate.
2. Description of Related Art
A hydrostatic continuously variable transmission which includes in combination an axial piston pump and axial piston motor is known from Japanese patent application Laid-Open No. 8-74962.
However, in the above conventional axial piston pump and axial piston motor, if the cylinder and the pistons are biased in opposite directions away from each other by a hydraulic pressure reaction, a tensile force acts on a casing as a result of a load transmitted from the cylinder to the casing and a load transmitted from the pistons to the casing. Therefore, if the casing is composed of a plurality of separate members integrally connected by bolts, it is necessary to increase the number or diameters of bolts in order to support the tensile force.